Comminuting device



June 4, 1968 HEGER 3,386,670

COMMINUTING DEVICE Filed Feb. 23. 1966 5 Sheets-Sheet 1 IN VENTOR:

Alois Heger BY flbnJl b June 4, 1968 A. HEGER 3, 6,

COMMINUTING DEVICE Filed Feb. 23, 1966 I5 Sheets-Sheet 2 lNvENToR: Alois Hcger BY In; 5' do:

June 4, 1968 A. HEGER 7 3,386,670

COMMINUTING DEVICE Filed Feb. 23. 1966 5 Sheets-Sheet 5 INVENTOR:

Alois Hagar United States Patent Claims. 61. 241-44 My present invention relates to a comminuting device and, more particularly, to an apparatus for the comminution of particulate materials and for converting such materials into finely divided masses. The invention has especial significance in the field of comminuting cereal grains, hay and the like to meals.

The grinding or milling of cereal grains has been effected heretofore in various types of grinding mills including disk mills, centrifugal mills-especially crossbeater, hammer and beater mills, and jaw-type mills. The apparatus in each case is relatively costly and gives rise to considerable dust so that is must be used in conjunction with special dust-separation devices (e.g. cyclonic dust traps) and the like. Moreover, the temperature of the comminuted mass undesirably raised by the frictional evolution of heat unavoidably accompanying the use of such devices.

It is, therefore, the principal object of the present invention to provide an apparatus for the comminution of particulate substances in which the frictional effect upon the material to be comminuted is held to a minimum so that there is substantially no rise in temperature of the comminuted mass, and forced-air dust separators or the like are unnecessary.

A corrolary object of this invention is to provide a device for the comminution of cereal grains, hay and the like to a meal of flour which does not require special preparations for separation of dust from the product.

A further object of this invention is to provide an apparatus of the character described which is of relatively simple construction, is capable of uniformly milling grains and the like, and has a relatively high throughput efficiency.

A further object of this invention is to provide a comminuting device for cereal grains and the like which is capable of producing a high-grade uniform product without greater supervision than has been required heretofore.

I have found that these objects and others which will become apparent hereinafter, can be attained in accordance with the principles of the present invention when the comminuting device comprises essentially a comminuting blade lying generally in a horizontal plane and rotatable at high speed about a vertical or upright axis and surrounded by a sieve structure, preferably closely spaced with respect to the blade. Thus the device of the present invention comprises an at least partly upwardly open housing having a vertical axis and adapted to receive with clearance a sieve structure surrounding the axis and the blade whose shaft preferably lies along the axis and extends into the structure from below. This arrangement permits the device to be constructed with a minimum cost and is capable of preventing, from all practical points of view, the meal dust from passing into the atmosphere and further ensures that the meal itself will not be ad versely warmed. The latter phenomenon appears to be a consequence of the fact that the comminution is carried out with such rapidity that the meal is effectively withdrawn from the system and the desired degree of comminution before frictional action of the blade upon the meal is able to raise its temperature.

According to a specific feature of this invention, the fineness of the meal obtained from the device can be varied by providing the sieve structures interchangeably within the housing. Thus, according to this aspect of the invention, the sieve can be constituted as a removable and interchangeable perforated sieve cylinder, the perforations of the cylinder being selected in accordance with the desired particle size of the meal. Advantageously, the interchangeable sieves can be removably mounted upon a cricular plate having a central aperture adapted to clear the blade shaft. As previously noted, the length of the blade is only slightly less than the diameter of the sieve structure so that the cylindrical perforated wall of the latter lies just out of the range of this blade while the housing structure itself may form a sleeve or shell spaced from the perforated cylindrical wall of the sieve structure with all-around clearance. The surrounding housin g, however, may be downwardly open to permit the corn rninuted product, after traversing the sieve, to fall into a receptacle or the like. It has been found, in practice, that the major portion of the meal passing the sieve moves through the perforations therein in the lower half of the sieve structure and that maintaining the height of the sieve approximately of the order of the radius of the blade and thus the radius of the cylindrical perforated sieve structure itself ensures that the vortex movement and turbulence of the meal will be held to a minimum with a consequent diminution of the heating action. In any event, this height of the sieve structure should be considered as an effective maximum.

According to a further feature of this invention, the inner wall of the cylindrical sieve is provided with a plurality of angularly spaced ribs, preferably extending along generatrices of the cylinder defined by the sieve. These ribs, which can be steel bars bolt-ed or welded to the metallic sieve structure, preferably project inwardly beyond the outer tips of the blades and can lie above the blades by a relatively small distance so that the blades just barely pass under these ribs. Such an arrangement has been found to markedly increase the efficiency of the milling operation, presumably as a consequence of the interference by the ribs with any entrainment of the meal by the blades. Best results have been found to obtain when the ribs are spaced apart by i.e. where four of them are provided at diametrically opposite locations of the sieve structure.

In accordance with another aspect of this invention, the plate of the sieve structure and the housing are mounted upon a rail of U-profile while the housing, comprising the shell mentioned above, also includes :a removable cover applied from above onto the shell and designed also to close the upwardly open sieve cylinder. The cover is mounted upon the housing shell by a clamping or locking means designed such that the cover can be removed rapidly for interchange or replacement of the perforated cylinder. After the cover is removed and the perforated cylinder is withdrawn from the assembly, the balance of the device can be rapidly cleaned. Advantageously, the plate, which is afiixed to the U-profile rail and the cover assembly are provided with formations engageable witl the cylindrical sieve structure for centering same within the housing.

The device is further provided with a feed means for continuously or intermittently supplying the particulate material to be comminuted to the interior of the sieve drum and the region of the blade. The feed device, according to this invention, comprises a centrally disposed tubular member whose axis coincides with that of the blade shaft and which can communicate with a dispensing hopper or funnel and extends through the cover into the interior of the cylindrical sieve. I have found that a feeding device of this character permits the efficiency of the device to be varied as may be required. Thus the feed device can be adjusted to permit the addition of more or less particulate material into the interior of the drum so that the level of the mass within the perforated drum is maintained substantially constant at any desired value. The quantity of particulate material within the drum determines, to a large measure, the operating efficiency of the assembly and so the further addition of such material by the feeding device may be regulated to maintain the quantity within the perforated drum at an optimum value. The adjustment of the feed means is effected, in accordance with this invention, by varying the axial location of the discharge outlet of the feed tube with respect to the blade means. Inasmuch as each of the perforated drum structures will permit a milling of the grain with a corresponding optimum efiiciency at only one position of the feed means (all other factors being constante.g. speed of the blade, diameter of the sieve), the feed tube can be telescopingly arranged in the housing structure and provided with index means or other indications to allow the feed tube to be set precisely upon change of the sieve structure. The adjusting means can, for example, comprise an inclined slot formed in an outer tube Wall and receiving a guide pin of the inner tube which, upon rotation of the iner or outer tubes, cams the pin upwardly or downwardly and thus adjusts the discharge-outlet height. The pin can be provided with a calmping device (eg. a screw or nut) in order to lock the outlet at the desired level. It has been found, moreover, that various types of grain may require feed tubes of different bore diameters. In order to avoid the need for special feed devices, it is possible and a feature of this invention, that the feed tube is mounted within the cover structure which, in turn, can be rapidly placed upon and removed from the housing shell via, for example, a bayonet coupling or the like.

In this manner, a plurality of cover structures can be employed, each with a respective feed tube of a specific bore diameter. As a safety factor, I provide a sensitive switch upon the housing structure for actuation by the cover assembly when the latter is put into place to prevent the motor of the blade means from being actuated until the cover is emplaced. This arrangement also ensures that the motor will be cut off when the cover is removed whereby the danger of a rotating blade during maintenance or cleaning is avoided. In order to prevent the accumulation of incompletely comminuted material between the blade and the plate of the sieve structure underlying same, it is advantageous to connect the plate to the support rail by screws whose heads extend above the plate to a region just below the blade means for disruption of any layer of material which otherwise might be packed below the blade. It is also desirable to affix the blades via nuts or the like to a threaded portion of the blade shaft which projects upwardly axially beyond the blades themselves so that the threaded portion of the shaft projecting beyond the blade and the nuts used to fasten the blade to the shaft together form an agitating mechanism which, advantageously, extends into the feed tube and ensures that the particulate material will be properly dispensed. The material to be comminuted then flows freely through this feed tube. The blade means can comprise a plurality of blade members with, advantageously, the free ends of these blades being bent upwardly at an acute angle to promote upward movement of the mass. When the device is used to comminute a fibrous material such as hay (eg. in the production of hay meal), it has been found to be ad vantageous to provide the leading edge of the blade with notches or indentations in the manner of a serrated knife. Best results are obtained, moreover, when the blade itself is inclined downwardly away from the cutting edge. The speed of the blade must, according to the present invention, be relatively high and advantageously lies between 5000 and 6000 revolutions per minute. In order to permit such high speeds to be obtained, the blade shaft is advantageously journaled in a bearing sleeve welded into the support rail and having roller bearings disposed be tween the shaft and the bearing sleeve. Below the sleeve,

the shaft can be provided with V-belt pulleys or the like permitting the coupling of the shaft to a motor via a suitable step-up transmission such as a V-belt whose drive pulley is mounted upon the motor.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is an elevational view of a comminuting device or mill, according to this invention;

FIG. 2 is a longitudinal cross-sectional view through the basic elements of this device; and

FIG. 3 is a cross-sectional view taken along the line IIIIII in FIG. 2.

As illustrated in the drawing, the comminuting device of the present invention comprises a housing structure generally designated by the reference numeral 1 which receives a generally cylindrical sieve 2 in the form of a perforated cylindrical plate Whose perforations are calibrated in accordance with the meal size desired. Thus, the sieve structure 2 includes the perforated cylinder 3 within which a blade 4 is journaled for rotation about a vertical axis upon the blade shaft 5, the blade 4 extending generally horizontally as will be evident from FIGS. 2 and 3. The housing 1 is open downwardly and is closable from above by a cover 6 which can be attached to the cylindrical shell 25 of housing 1 by a bayonet formation represented at 6' in FIG. 2. Thus the cover 6 can rapidly be mounted upon and removed from the housing 1 and is clamped thereto when in place. The cover 6 is provided with a telescoping feed arrangement including a tube 7 which extends coaxially with the shaft 5 upwardly from the cover 6 and receives a vertically shiftable tube 10 for feeding the material to be comminuted to the region of the blades 4. The axis of the device is illustrated at 9.

The assembly described above is mounted upon a bin 12 adapted to hold the rough-ground meal, this bin carrying a drive motor 13 whose shaft 14 extends vertically and is offset from the shaft 5 but provided with drive pulleys 15. A transmission means including V-belts 19 connect the drive pulleys 15 with the driven pulleys 18 afiixed to shaft 5 (FIGS. 1 and 2). At the other extremity 16 of the shaft of motor 13, a blower wheel or fan blade 17 is mounted. A housing 20 forms a protective enclosure for the belts 19 (FIG. 3) and has downwardly inclined surfaces so as to prevent any obstruction of the downward movement of the meal from the compartment surrounding the sieve cylinder 3 into the bin 12. The drive pulleys 15 can be of relatively large diameter while the driven pulleys 18 are of a relatively small diameter so that the transmission between the motor 13 and the shaft 5 is a speed-increasing system.

From the bin 12, a tube 21 extends to the blower 17 and is provided with a pivotal flap 22 (FIG. 1). The blower 17 can thus draw the rough-ground meal from the bin 12 and supply it via the discharge tube 23 to a mixing or feeding device as may be desired. Additionally, the bin 12 is provided with an openable cover 24 through which access to the interior of the bin is possible. This arrangement permits the meal to be dispensed manually.

Referring again to FIG. 2, it will be seen that the housing 1 includes the cylindrical shell 25 which, along its underside, carries a circular ring 26 of angle profile with one leg of this ring secured to the shell 25 while the other leg is aifixed to an inverted-U support rail 27. This rail extends along a diameter of the shell 25 and is aflixed thereto by welding at the ring 26.

A hearing sleeve or bushing 28 is inserted into the rail 27 centrally with respect to the shell 25 and is attached to the rail 27 by welding. The sleeve 28 contains a pair of ball bearings 29 which journal the shaft 5 for rotation about a vertical axis on the rail 27 and in the housing 2 528. A central plate 30 overlies the rail 27 and is of disk-shaped configuration and connected with the rail by bolts 31 whose heads project above the floor of the cylindrical sieve structure 3 formed by this plate 30. The circular plate thus prevents the goods to be comminuted from falling into the bin 12 until it has been comminuted to the proper size and passes through the perforations of the sieve. Along the periphery of the plate, there is provided a circular boss 32 upon which the cylindrical sieve 3 is centered, the height of this cylinder 3 being so dimensioned that the closed cover 6 holds the cylinder against the plate 30.

The centering of this cylinder 3 is improved by providing a centering ring or boss 33 upon the cover 6, the inner face of the centering ring being of inwardly convergent frusto-conical configuration, i.e. upwardly tapering, so that a self-centering and clamping action is obtained. The cylinder 3 thus wedges slightly into the cover 6 and can be removed therewith from the housing 1 without difiiculty inasmuch as this cylinder merely rests upon the plate 30 when in place. The cylinders 3 can thus be easily interchanged so that sieve structures of different meshes or sieve sizes can be employed in accordance with the fineness of the meal desired. The cylindrical sieves 3 are also provided with upright ribs 35 along the inner wall of the cylinder at four equispaced locations as illustrated in FIGS. 2 and 3.

The tube 7 can be welded to the cover 6 or detachably and interchangeably mounted thereon, and serves as a guide for the feed tube 10 which, as previously indicated is movable along the axis 9. The adjustment of this tube 10 is effected by means of an inclined slot 36 provided in the tube 7 and slidably receiving a bolt 37 which projects through the tube and can be manually shifted to angularly displace the tube 10 to which the pin 37 is attached. It will thus be understood that the tube 10 is cammed upwardly or downwardly depending upon the sense of its rotation, to adjust the height of its outlet above the blades 4. When the tube 10 is moved downwardly, the mouth of this tube lies closer to the blades 4 and the flow particulate material into the milling chamber is reduced. When this tube is raised, this flow increases. A funnel 38 mounted upon the tube 7, whose axis 8 coincides with the axis 9 of the feed tube 10, serves to supply the comminutable material to tube 10. A sensitive switch 13' on the shell 25 is operable by removal of the cover 6 to inactivate the motor 13 as represented by dot-dash lines 13".

The blade means 4 is fastened upon the shaft 5 against a shoulder 39 by means of nuts 41 threaded onto the upwardly projecting end of shaft 42 so as to clamp a disk or washer against the plate. The threaded extremity 42 of the shaft and the nuts 41 form an agitator extending partly into the mouth of the feed tube 10 and thus facilitate the dispensing of the particulate material. The blade 4 is so arranged that it lies just slightly above the heads 43 of the bolts or screws 31 so that accumulation of uncomminuted material below the blade and the packing of such material by the blade is prevented by the interference of these bolt heads or projections.

The outer extremities of the blade 4 are bent upwardly and tend to throw the meal upwardly so that the goods repeatedly descend and come into engagement with the blades at high speed. Moreover, the leading or cutting edge of the blades (two such blades being provided at diametically opposite sides of the shaft 5 as iilu'strated in FIG. 3) is formed with serrations 44 which are especially effective for the comminution of fibrous material as indicated earlier. A hard-facing process may be employed to apply a hardened material (e.g. tungsten carbide) to the cutting edge of the blades prior to sharpening or subsequently thereto. Bores 45 may be provided in the angle ring 26 to permit the shell 25 to be mounted directly upon the bin 12 of the rail 27 is to be omitted. In that case, a spider or the like may be provided upon the housing structure in order to support the bearing assembly 28, 29. The cylindrical gap between the shell 25 and the perforated sieve 3 is open downwardly at 46 through which the downwardly open portion 46 falls into the bin 12. The perforations 34 of the sieve 3 define the size of the meal resulting inasmuch as only meal of the desired patricle size can pass into the clearance between the shell 25 and the sieve 3, the remainder of the mass being retained within the sieve until the completion of its comminution. Interchange of the sieve cylinders 3 permits the caliber of the meal to be modified at will.

I claim:

1. A comminuting device comprising housing means forming a receptacle for a comminuted material, said housing means including an enclosure communicating with said receptacle; an annular sieve structure surrounding an upright axis and disposed in said enclosure for discharging comminuted material passing through said sieve structure into said receptacle; blade means extending generally transversely to said axis but rotatable thereabout within said sieve structure for comminuting a particulate mass to form the comminuted material traversing said sieve structure; and feed means for supplying said particulate mass to said blade means within said sieve structure said enclosure including a generally cylindrical shell with a downwardly open bottom communicating with and overlying said receptacle, said sieve structure including a plate disposed within said shell and along the open bottom thereof with annular clearance from said shell.

2. A comminuting device as defined in claim 1 wherein a cylindrical sieve is removably mounted on said plate and interchangeable to vary the sieve-aperture size, said shell and said cylindrical sieve being substantially coaxial with said blade means; said blade means including an axially extending shaft projecting into the interior of said sieve structure through said plate.

3. A comminuting device as defined in claim 2 wherein said cylindrical sieve has an axial height corresponding substantially to its radius.

4. A comminuting device as defined in claim 2 wherein said sieve structure further comprises a plurality of angularly spaced ribs provided along the inner surface of said cylindrical sieve and extending generally along respective generatrices thereof.

5. A comminuting device as defined in claim 2 wherein said eenclosure includes a support rail spanning the open bottom of said shell and carrying said plate and said cylindrical sleeve, said shell having a mounting ring of angular cross-section with one leg connected with said shell and another leg secured to said rail, said plate being bolted to said rail and said shaft passing therethrough, said rail having a bearing sleeve coaxial with and surrounding said shaft, said device further comprising roller bearings within said sleeve for journalling said shaft therein.

6. A comminuting device as defined in claim 2 wherein said enclosure includes removable cover means mountable upon said shell for closing same, said feed means being carried by said cover means, said cover means and said plate being provided with centering formations for positioning said cylindrical sieve and clamping said cylindrical sieve between said cove-r means and said plate upon emplacement of said cover means.

7. A comminuting device as defined in claim 6 wherein said feed means includes a feed tube mounted upon said cover means substantially coaxially with said shaft and provided with a hopper for supplying said particulate mass to said sieve structure, an axially shifta'ble further tube in telescoping relationship with said feed tube and having a discharge mouth movable toward and away from said blade means in alignment with said shaft, and means for axially shifting said further tube toward and away from said blade means and for clamping said further tube in a selected position with respect to said bade means.

8. A comminuting device as defined in claim 6 further comprising electrically operable motor means mounted upon said housing means; transmission means coupling said motor means with said shaft; and switch means operable by said cover means upon removal of. same for deactivating said motor means upon opening of said enclosure.

9. A comminuting device as defined in claim 8 wherein said receptacle is a bin for accumulating with comminuted material, said device further comprising blower means operable by said motor means for discharging said comminuted material from said bin.

10. A comminuting device as defined in claim 6 wherein said blade means includes at least one blade extending close to said plate along a radius of said cylindrical sieve, said plate being provided with projections upstanding therefrom to prevent the accumulation of incompletely comminuted material below said blade, the free end of said blade being turned upwardly to impart to the mass within said cylindrical sieve an upward movement during comminution by said blade, said blade having a serrated cutting edge, said shaft extending into the mouth of said further tube and forming an agitator therein to facilitate continuous flow of said particulate mass into said sieve structure.

References Cited UNITED STATES PATENTS 2,474,314 6/ 1949 Koehne 241-74 2,886,254 5/1959 Rohlinger et al. 24174 2,973,153 2/1961 Rich 241-74 3,210,016 10/1965 Sevin et al 24174 GERALD A. DOST, Primary Examiner. 

1. A COMMINUTING DEVICE COMPRISING HOUSING MEANS FORMING A RECEPTACLE FOR A COMMINUTED MATERIAL, SAID HOUSING MEANS INCLUDING AN ENCLOSURE COMMUNICATING WITH SAID RECEPTACLE; AN ANNULAR SIEVE STRUCTURE SURROUNDING AN UPRIGHT AXIS AND DISPOSED IN SAID ENCLOSURE FOR DISCHARGING COMMINUTED MATERIAL PASSING THROUGH SAID SIEVE STRUCTURE INTO SAID RECEPTACLE; BLADE MEANS EXTENDING GENERALLY TRANSVERSELY TO SAID AXIS BUT ROTATABLE THEREABOUT WITHIN SAID SIEVE STRUCTURE FOR COMMINUTING A PARTICULATE MASS TO FORM THE COMMINUTED MATERIAL TRAVERSING SAID SIEVE STRUCTURE; AND FEED MEANS FOR SUPPLYING SAID PARTICULATE MASS TO SAID BLADE MEANS WITHIN SAID SIEVE STRUCTURE SAID ENCLOSURE INCLUDING A GENERALLY CYLINDRICAL SHELL WITH A DOWNWARDLY OPEN BOTTOM COMMUNICATING WITH AND OVERLYING SAID RECEPTACLE, SAID SIEVE STRUCTURE INCLUDING A PLATE DISPOSED WITHIN SAID SHELL AND ALONG THE OPEN BOTTOM THEREOF WITH ANNULAR CLEARANCE FROM SAID SHELL. 